We've been talking about this a bit and we have a bit of a theory:

We were just recently added to the Flash white list for IE 10 non-Desktop. There's a chance that if your machine doesn't have that most up to date list, it's not letting our fall back Flash player load since it thinks that Channel 9 isn't allowed to use Flash content. We're looking at some ways to check  your version of the list or how to get it to update. One method that worked for Duncan was to go to another site that's on the white list (in this case new Star Wars owners Disney) and then come back to Channel 9.